Race condition in the ext4_file_write_iter function in fs/ext4/file.c in the Linux kernel through 3.17 allows local users to cause a denial of service (file unavailability) via a combination of a write action and an F_SETFL fcntl operation for the O_DIRECT flag.
lists.opensuse.org/opensuse-security-announce/2015-09/msg00004.html
rhn.redhat.com/errata/RHSA-2015-0290.html
rhn.redhat.com/errata/RHSA-2015-0694.html
www.openwall.com/lists/oss-security/2014/10/09/25
www.securityfocus.com/bid/70376
www.spinics.net/lists/linux-ext4/msg45683.html
www.spinics.net/lists/linux-ext4/msg45685.html
bugzilla.redhat.com/show_bug.cgi?id=1151353
exchange.xforce.ibmcloud.com/vulnerabilities/96922
lkml.org/lkml/2014/10/8/545
lkml.org/lkml/2014/10/9/129